train timing

i m santosh from vellore tamilnadu. i wants to know why chennai to banglore, and chennai to trevendram  trains always late. i seen branvan exp. its morning started 7:15am from chennai, its its have to come 6:30am in pf. but its comes 7:20am, and its starts 7:45am. tham mean departure time also late then how can its reach in proper time.nobody can ask it, bez its indian railway. and see chennai central now everywhere parcel keeps. passenager cant walk properly. i want to know its pessanger station or parcel train. always says indain railway always in profit. i wants to know what impliment now till 1956 to 2008. we can see in road vehicals and we can see train. on train its taking time chennai central to katpadi station 2:30hr exp train in between 3-4 stops. and one train its superfast exp. no any stoping chennai central to katpadi, its also taking 2:30hr.
i want to know then what is diffrents sfast and exp train. plz i want to know it. its not one day. its always. bez nobody can ask it. totaly railways department not well. 1st plz come in time. if u think ur now going in profit then i wants to say no. bez pessanger not reach his goal at right time. plz i want to say do ur work properly. time is most imp thing in life. plz save time its my request